1. Technical Field
The present disclosure relates to signal conversion. More particularly, the present disclosure relates to signal conversion of consumer electronics connection protocols.
2. Description of Related Art
In terms of signal transmission, traditional copper wire cables impose limits on signal transmission distance and signal quality. At present time, various protocols of consumer electronics connection have been developed and tend to use more and more signal pins. For example, the Universal Serial Bus (USB) 3.0 standard utilizes three pairs of differential signals, and one differential pair utilized by the USB 2.0 standard is bi-directional. A digital-only connector based on the Digital Video Interactive (DVI) standard has three or six transition-minimized differential signaling (TMDS) data channels, a TMDS clock channel, a Display Data Channel (DDC) channel and hot plug detect. The DDC is bi-directional. The High-Definition multimedia Interface (HDMI) 1.4a standard includes three or six TMDS data channels, a TMDS clock channel, a DDC channel, a Consumer Electronics Control (CEC) channel, a HDMI Ethernet and Audio return Channel (HEAC) channel and hot plug detect. The DDC, CEC and HEAC channels are bi-directional.
The form factor of existing consumer electronics protocols-based connectors tends to be overly large to be accepted by receptacles of popular handheld devices. To render the connectors smaller, one approach is to bundle the high/low-speed data, clock, control signals into a high speed signal so that the pin count can be reduced.
The data rate of these signals in consumer electronics, transmitted over copper wires, is much slower than the available data rate of optical communication. Features of optical communication include: high bandwidth, fixed data rate, better signal quality and long signal transmission distance. Although optical fibers support bi-directional transmission with dense wavelength multiplexing (DWM), optical devices such as photodiodes, vertical-cavity surface-emitting lasers (VCSEL) and laser diodes do not. Moreover, one channel of optical connection is generally much more expensive than a copper wire. Thus, it is desirable and would be cost effective to convert all the signals transmitted in consumer electronics connection into one or more high-speed signals which are suitable for optical communication.